Pyrotechnic gyro



Oct. 25, 1966 H. v. FRIELINK 3,280,643

PYROTECHNIC GYRO Filed Oct. 21, 1963 5 Sheets-Sheet 2 INVENTOR. HENRY V. FF?! ELINK ATTORNEY Oct. 25, 1966 H. v. FRIELINK 3,280,643

PYROTECHNIC GYRQ Filed Oct. 21, 1965 a Sheets-Sheet 5 a sa 33s I 75 Q V 80 u 72 7O 78 1 INVENTOR.

HENRY V. FRIELINK ATTORNEY United States Patent ()fiice 3,280,643 Patented Oct. 25, 1966 3,280,643 PYROTECHNIC GYRO Henry V. Frielink, Grand Rapids, Micln, assignpr to C. Allen Business Machines, Inc., Grand Rapids, Mich, a corporation of Michigan Filed Oct. 21, 1963, Ser. No. 317,659 18 Claims. (Cl. 74-55) This invention relates in general to a gyro, and more particularly to a gas-powered gyro, and still more particularly to a gas-powered gyro utilizing a propulsive or explosive charge for power. A gyro of the type of the present invention may be referred to as a pyrotechnic gyro.

The gyro of the present invention is particularly useful in airborne vehicles wherein the vehicles time in the air is relatively short-lived. Specifically, the gyro of the present invention is useful in missile guidance systems or the like, although other uses and purposes may be apparent to one skilled in the art.

Heretofore, spring-powered gyros have been employed where only short periods of life were required, but most spring-powered gyros have inadequate speed and consequently decay quickly, thereby limiting their life and usefulness. Moreover, such spring-powered gyros have been relatively complex and have included a large number of precision parts thereby making such gyros expensive to construct.

It is therefore an object of this invention to provide a pyrotechnic gyro which obviates the difficulties heretofore encountered in spring-powered gyros and heretofore developed pyrotechnic gyros.

Another object of this invention resides in the provision of a pyrotechnic gyro having a relatively small number of precision parts and being capable of extremely high rates of speed to effectively prolong useful life.

A further object of this invention is in the provision of an improved pyrotechnic gyro that is less expensive to construct than spring-wound gyros and more efficient than other pyrotechnic gyros.

A still further object of this invention is to provide an improved pyrotechnic gyro that may be reloaded for reuse.

Another objeet of this invention is in the provision of a pyrotechnic gyro that requires less weight and space to obtain equal or superior results as from heretofore developed pyrotechnic gyros.

Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts, in which:

FIG. 1 is a perspective view of the gyro according to the present invention;

FIG. 2 is an end view of the gyro of FIG. 1;

FIG. 3 is a longitudinal sectional view taken through the gyro of FIG. 1 and substantially along line 3-3 of FIG. 2;

FIG. 4 is a transverse sectional view taken through the gyro of the present invention and substantially along line 44 of FIG. 3;

FIG. 5 is a detail fragmentary view illustrating the position of a splined bolt actuator after the gyro has been uncaged and fired;

FIG. 6 is a detail fragmentary view illustrating the manner of obtaining access to the propulsive or explosive charge for firing same;

FIG. 7 is a detail and enlarged sectional view taken substantially along line 77 of FIG. 3;

FIG. 8 is a detail and elevational view of the gyro with an end cover removed;

FIG. 9 is a sectional view taken through a modified rotor and splined bolt actuator arrangement;

FIG. 10 is an axial sectional view taken through a gyro of the present invention and showing a modified mechanism for guiding the splined bolt actuators when they are fired from the rotor;

FIG. 11 is an end view of the mechanism for guiding the splined bolt actuators, and taken substantially along line 11-11 of FIG. 10; and

FIG. 12 is a top plan view of the splined bolt actuator guide mechanism and showing the securing of the mechanism after the gyro has been fired.

Referring now to the drawings and particularly to FIGS. l-4, an illustration of the gyro of the present invention is shown which includes in general a casing 20 comprised of a pair of substantially identical cup-shaped halves or covers 21 and 22 fitted over a frame 23. The cup-shaped halves 21 and 22, respectively, include cylindrical side walls 21a and 22a, and end walls 21b and 22b. At the open ends of the halves, radially extending flanges 21c and 22c coact with an annular ridge 23a of the frame 23. Suitable fastening means 24, FIGS. 1 and 2, secure the flanges 21c and 220 to the ridge 23a. The frame 23 includes a cylindrical portion 23b integral with the ridge 23a and which guidably supports the cylindrical Walls 21a and 22a of the cup-shaped halves 21 and 22.

Axially aligned trunnions 25 and 26 having external threads are adjustably received in coaxially aligned threaded bores 27 and 28, respectively. The bores are arranged in thickened portions 230 along the ridge 23a of the frame 23 and at the center thereof. Trunnion caps 25a and 26a are threadedly received in the bores 27 and 28 to lock the trunnions in place and to seal against the entrance within the casing of unwanted matter. The trunnions 25 and 26 bearingly support an outer gimbal 29. An inner gimbal 30 is provided with trunnions 31 and 32 in coaxial alignment, which trunnions are bearingly supported in the outer gimbal 29 along an axis perpendicu lar to the axis of support of the outer gimbal. A rotor 33 is bearingly supported in the inner gimbal 30 along an axis normal to the axis of support of the inner gimbal. Thus, rotation of the rotor 33 will be about an axis perpendicular t0 the pivotal axis of the inner gimbal 30 and the pivotal axis of the outer gimbal 29, while the pivotal axis of the outer gimbal 29 is perpendicular to the outer axis of the inner gimbal 30.

The gyro being herein describe-d, because of having inner and outer gimbals, is a free gyro, although it should be appreciated that the present invention may also be employed with rate gyros where only a single gimbal is provided.

As may be seen particularly in FIG. 3, the rotor 33 includes first and second sections 34 and 35 held together by means of a screw-threaded arrangement 36. Stub shafts 37 and 38 coaxially extend from the sections 34 and 35, respectively, and are bearingly received by the inner gimbal 30. It should be appreciated that when the sections 34 and 35 are screwed together as shown in FIG. 3, a unitary rotor is provided.

The sections 34 land 35 are provided with helically splined bores 39 and 40, respectively, which are adapted to receive therein in mating engagement helically splined bolt actuators or shafts 41 and 42. The helically splined or threaded bolts and bores are arranged so that upon forcing the bolts outwardly, they will coact to spin the rotor 33 in one direction. Thus, the bolt actuators 41 and 42 are of opposite hand, as are their respective bores 39 and 40. In the embodiment of FIGS. 1-4, the helically splined bolt actuators 41 and 42 are provided with flat opposed end faces 41a and 42a that are adapted to be in spaced relation when the bolt actuators are positioned in the rotor prior to the firing of the gyro to thereby define a cavity 43 within the rotor which receives a propulsive or explosive charge 44. This charge may be of any suitable material such as cordite and may be molded or otherwise formed to fit intimately within the cavity 43. The helically splined bores 39 and 40 terminate inward- 1y of the rotor at the boundaries of the cavity 43 so that the charge 44 may take a cylindrical shape. .The charge 44 would be inserted into the cavity 43 prior to assembling of the sections 34 and 35 of the rotor 33, while the bolt actuators may thereafter be inserted after assembling the rotor and mounting same in the inner gimbal 30. Thus, it can be readily appreciated that once the gyro is fired, it may be reloaded with another charge 44 for future firing.

End plates 45 and 46 are provided at the opposite ends of the frame 23 and are suitably fitted to the frame and held in place after the cup-shaped halves or covers 21 and 22 are secured in place to the frame. 48 are provided for additionally securing the end plates to the cover when the covers are in place over the frame. Splined bolt actuator guides 49 and 50 are respectively mounted on the end plates 45 and 46 and respectively adapted to coact with the splined bolt actuators 41 and 42 during the firing of the gyro. The guides 49 and 50 include cylindrical bores 49 and 50, respectively, sized to freely receive the splined bolt actuators, and diametrically opposed slots 4% and 50b which slidably receive guide pins 51 and 52 secured to the splined bolt actuators 41 and 42, respectively. Thus, the splined bolt actuator guides 49 and 50 prevent rotation of the splined bolt actuators 41 and 42, respectively, and serve to hold the bolt actuators when the gyro has been fired. And since only linear motion of the splined bolt actuators 41 and 42 is permitted, the rotor 33 will be caused to spin when the bolt actuators are forced outwardly after ignition of the charge 44.

The splined bolt actuator guides 49 and 50 are suitably flanged at 49c and 500 so that they may be connected to the end plates 45 and 46, respectively, by suitable fasteners 53 and 54. The guides further extend through the end plates and project on each side thereof as may be most clearly seen in FIG. 3.

In order to prevent return of the splined bolt actuators 41 and 42 toward the rotor 33 after the gyro has been fired, since such a return would interfere with the rotation of the rotor, spring clips 55 (only illustrated in connection with the guide 50) are mounted at the outer ends of the guide pin slots to receive and hold the guide pins such as the guide pin 52 as shown in FIG. 5, when the gyro has been fired and the bolt actuators have been forced to their outer positions.

Knockouts 56 and 57 are provided in the casing end Walls 21b and 22b which are dislodged by reduced end portions 41b and 42b of the splined bolt actuators 41 and 42 when the gyro has been fired. Note particularly FIG. wherein the bolt actuator 42 is shown in fired position as being held by the clips 55 and wherein the reduced end portion 42b has dislodged the knockout 57 to thereby permit the escape of gases from within the gyro casing.

An example of how the charge 44 may be ignited is shown in FIGS. 3 and 6, wherein an ignition wire 53 extends through a hole in the rotor 33 and into the charge 44, and is connected to a spring wire 59 that is secured to an insulating panel 60. The spring wire 59 is suitably connected to a source of electrical potential for firing the charge 44. In initially readying the gyro for firing, it is necessary to cage the rotor 33 to thereby hold the splined bolt. actuators 41 and 42 in tight against the charge 44 until the charge is fired. The spring wire 59 engages in the hole in the rotor 33 to connect to the ignition wire 58, thereby to hold the rotor 33 in caged position. When the charge 44 is fired, the spring wire 59 breaks loose and snaps out of the path of movement of the rotor 33 ,as shown in dotted lines in FIG. 6. The ignition wire may also be brought into the rotor in an- Fasteners 47 and 4, other manner as will be hereinafter explained with another embodiment.

In operation, the gyro is held in caged position, as

illustrated in FIG. 3, by means of the spring wire 59, and

wherein the spline-d boltactuators 41 and 42 are tight in against the charge 44. Upon electrically igniting the charge 44 through the ignition wire 58 and the spring wire 59, the gases generated force the splined bolt actuators 41 and 42 outwardly at'a high rate of speed to spin the rotor 33 and thereby power the gyro. The splined bolt actuators 41 and 42 are held in their outer positions by the spring clips 55 and the knockouts 56 and 57 are displaced by the splined bolt actuators to permit the escape of gases generated from the charge 44.

Referring now to FIG. 9, a modified rotor 33A is shown which differs from the rotor 33 in that it is constructed of one piece, and in that the helically splined bores 61 and 62 extend inwardly to the center of the rotor. Further, the splined bolt actuators 63 and 64 of this embodiment differ from the splined bolt actuators 41 and 42 in that the splined bolt actuator 63 is provided with a hollow interior or blind bore 65 for receiving a charge 66. The charge 66 completely fills the blind bore or cavity 65 andtherefore is tight against the face 64a of the opposing splined bolt actuator 64. In this embodiment, an ignition wire 67 is provided which extends through a hole formed in the splined bolt actuator 63 for the purposes of igniting the charge 66, and this manner of wire placement is preferred to avoid any possible rotor unbalance. It should be appreciated that a blind bore may also be provided in the bolt actuator 64 so that the charge is supported by both bolt actuators. This embodiment will operate identical to the embodiment of FIGS. 1-4, however, it is not necessary to disassemble the rotor for reloading or to even take the rotor out of the inner girnbal. It is only necessary to place the charge in the splined bolt actuator 63 and position the splined bolt actuators 63 and 64 properly within the rotor 33A.

Referring now to the embodiment of FIGS. 10-42, a modified rotor and bolt actuator guide and retaining mechanism is shown, these differing from the previous embodiments. includes sections 68 and 69 which are secured together by a plurality of fasteners 70. The sections coact to define a civity 71 for receiving the charge 72. Like numerals are employed in all embodiments where like parts are described.

The mechanism in this embodiment employed for guiding the splined bolt actuators 41 and 42 during the ejection from the rotor 33B, and preventing rotation of the bolt actuators comprises a linkage assembly 73. This linkage assembly is identical at both sides of the gyro and for each splined bolt actuator 41 and 42, and accordingly only the arrangement at one side will bedescribed in detail. The linkage arrangement includes an upper double link 74 pivotally carried on a pin 75 mounted in the end plate 76 .at one end and pivotally mounted at the other end to a pin 77 fixed to the outer end of the bolt actuator 42. Slots 78 are provided in the upper ends of the double link 74 to additionally define a slidable relation with the pin 75. A lower double link 79 identical to the upper double link 74 is pivotally mounted at one end to the bolt pin 77, and pivotally and slidably mounted at the other end to a pin 80 secured in the end plate 76. A suitable slotted opening 81 is provided in sembly 73 prevents rotation of the bolt actuator 42 when the gyro is fired to thereby cause the rotor 33B to spin, while at the same time guiding the movement of the bolt actuator 42 as it leaves the rotor 33B. After the gyro I has been fired, and the bolt actuators 41 and 42 have left the rotor 33B, the bolt actuators will swing down The rotor 33B is split or sectional and wardly to a position as shown by the bolt actuator 41 in dotted lines in FIG. 10.

A bracket 82 functions as a stopper for the bolt actuators when they are in the fired position, and spring clips 83 are mounted on the end plates and positioned to prevent return of the linkage arrangement after the gyro has been fired as shown'particularly in FIG. 12. The spring clips 83 interfere with the pins 77 to prevent return of the linkage. Actually the pins 77 push the spring clips 83 apart as the bolt actuator moves to its completed fired position and against the stopper 82, after which the clips 83 spring inwardly to block return movement of the pins 77. It should be appreciated that any other type of mechanism may be employed which prevents rotation of the splined bolt actuators 41 and 42 when they are fired and which guides their movement and prevents their return to interfere with the operation of the rotor. While not shown, an ignition wire may be brought in through the rotor or through a splined bolt actuator to electrically ignite the charge 72. Further, knockouts may be provided to permit the escape of gas after the gyro has been fired.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.

The invention is hereby claimed as follows:

1. A pyrotechnic gyro comprising a frame, a gimbal pivotally mounted within said frame, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of said gimbal, a pair of aligned helically splined bores of opposite hand in said rotor coaxial with the axis of rotation thereof, a pair of helically splined bolt actuators of opposite hand mating with said bores, means connected to said frame for preventing rotation of said actuators, and a propulsive charge within said rotor for ejecting the actuators from the bores to thereby impart a rotational spin to said rotor upon ignition thereof.

2. A pyrotechnic gyro comprising a frame, a gimbal pivotally mounted Within said frame, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of said gimbal, a pair of aligned helically splined bores of opposite hand in said rotor coaxial with the axis of rotation thereof, a pair of helically splined bolt actuators of opposite hand mating with said bores, means connected to said frame for preventing rotation of said actuators, a propulsive charge within said rotor for ejecting the actuators from the bores to thereby impart a rotational spin to said rotor upon ignition thereof, and means for preventing said actuators from interfering with the rotation of said rotor after ejection of said actuators from said rotor.

3. A pyrotechnic gyro comprising a frame, a gimbal pivotally mounted within said frame, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of said gimbal, a pair of aligned helically splined bores of opposite hand in said rotor coaxial with the axis of rotation thereof, a pair of helically splined bolt actuators of opposite hand mating with said bores, means connected to said frame for preventing rotation of said actuators, a propulsive charge within said rotor for ejecting the actuators from the bores to thereby impart a rotational spin to said rotor upon ignition thereof, and means for holding said actuators out of contact with said rotor after ejection of the actuators therefrom.

4. A pyrotechnic gyro comprising a. frame, a gimbal pivotally mounted within said frame, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of said gimbal, a pair of aligned helically splined bores of opposite hand in said rotor coaxial with the axis of rotation thereof, a pair of helically splined boltactuators of opposite hand mating with said bores, means connected to said frame'for preventing rotation of said actuators, a propulsive charge within said rotor for ejecting the actuators from the bores to thereby impart a rotational spin to said rotor upon ignition thereof, and means for holding said actuators out of contact with said rotor after ejection of the actuators therefrom, said holding means including a pin on each of said actuators coacting with spring means mounted on said frame.

5. A pyrotechnic gyro comprising a frame, a gimbal pivotally mounted within said frame, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of said gimbal, a pair of aligned helically splined bores of opposite hand in said rotor coaxial with the axis of rotation thereof, a pair of helically splined bolt actuators of opposite hand mating with said bores, means connected to said frame for preventing rotation of said actuators, said means including guiding means mounted on said frame for guiding the movement of the actuators during ejection from the rotor, and a propulsive charge within said rotor for ejecting the actuators from the bores to thereby impart a rotational spin to said rotor upon ignition thereof.

6. A pyrotechnic gyro comprising a frame, a gimbal pivotally mounted within said frame, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of said gimbal, a pair of aligned helically splined bores of opposite hand in said rotor coaxial with the axis of rotation thereof, a pair of helically splined bolt actuators of opposite hand mating with said bores, means connected to said frame for preventing rotation of said actuators, said means including hollow guide brackets slidably receiving said actuators during ejection from the rotor, and a propulsive charge within said rotor for ejecting the actuators from the bores to thereby impart a rotational spin to said rotor upon ignition thereof.

7. A pyrotechnic gyro comprising a frame, a gimbal pivotally mounted within said frame, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of said gimbal, a pair of aligned helically splined bores of opposite hand in said rotor coaxial with the axis of rotation thereof, a pair of helically splined bolt actuators of opposite hand mating with said bores, means connected to said frame for preventing rotation of said actuators, said means including toggle linkage arrangements connected to the outer ends of said actuators, and a propulsive charge within said rotor for ejecting the actuators from the bores to thereby impart a rotational spin to said rotor upon ignition thereof.

8. A pyrotechnic gyro comprising a frame, a gimbal pivotally mounted within said frame, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of said gimbal, a pair of aligned helically splined -bores of opposite hand in said rotor coaxial with the .axis of rotation thereof, a pair of helically splined bolt actuators of opposite hand mating with said bores, means connected to said frame for preventing rotation of said actuators, and a propulsive charge within said rotor for ejecting the actuators from the bores to thereby impart a rotational spin to said rotor upon ignition thereof, said rotor being sectional so that it may be disassembled to insert the charge.

9. A pyrotechnic gyro comprising a frame, a gimbal pivotally mounted within said frame, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of said gimbal, a pair of aligned helically splined bores of opposite hand in said rotor coaxial with the axis of rotation thereof, a pair of helically splined bolt actuators of opposite hand mating with said bores, means connected to said frame for preventing rotation of said actuators, and a propulsive charge within said rotor for ejecting the actuators from the bores to thereby impart a rotational spin to said rotor upon ignition thereof, said rotor being one-piece and one of said actuators being hollow at the inner end to receive the charge.

10. A pyrotechnic gyro comprising a frame, a gimbal pivotally mounted within said frame, a rotor rotatably mountedin said gimbal along an axis normal to the pivot axis of said gimbal, a pair of aligned helically splined bores of opposite hand in-said rotor coaxial with the axis of rotation thereof, a pair of helically splined bolt actuators of opposite hand mating with said bores, means connected to said frame for preventing rotation of said actuators, a propulsive charge within said rotor for ejecting the actuators from the bores to thereby impart a rotational spin to said rotor upon ignition thereof, and an ignition wire extending from said charge and being connectable to a source of electrical energy. 7

11. A pyrotechnic gyro comprising a frame, a gimbal pivotally mounted within said frame, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of said gimbal, a pair of aligned helically splined bores of opposite hand in said rotor coaxial with the axis of rotation thereof, a pair of helically splined bolt actuators of opposite hand mating with said bores, means connected to said frame for preventing rotation of said actuators, a propulsive charge within said rotor for ejecting the actuators from the bores to thereby impart a rotational spin to said rotor upon ignition thereof, said rotor being one-piece and one of said actuators being hollow at the inner end to receive the charge, and an ignition wire extending through said hollow actuator and being connectable to a source of electrical energy.

12. A pyrotechnic gyro comprising a frame, a casing surrounding said frame, a gimbal pivotally mounted within said frame, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of said gimbal, a pair of aligned threaded bores of opposite hand in said rotor coaxial with the axis of rotation thereof, a pair of threaded bolt actuators of opposite hand mating with said bores, means connected to said frame for preventing rotation of said actuators but allowing same to be ejected from the bores, and a propulsive charge within said rotor for ejecting the actuators at a high rate of speed from the bores to thereby impart a rotational spin to said rotor upon ignition thereof.

13. A pyrotechnic gyro comprising a frame, a casing surrounding said frame, a gimbal pivotally mounted within said frame, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of said gimbal, a pair of aligned threaded bores of opposite hand in said rotor coaxial with the axis of rotation thereof, a pair of threaded bolt actuators of opposite hand mating with said bores, means connected to said frame for preventing I rotation of said actuators but allowing same to be ejected from the bores, and a propulsive charge within said rotor for ejecting the actuators at a high rate of speed from the bores to thereby impart a rotational spin to said rotor upon ignition thereof, and a knockout in said casing operable by the ejection of an actuatorfor permitting the escape of gases generated by the charge. 7

14. A pyrotechnic gyro comprising a frame, a casing surrounding said frame, a gimbal pivotally mounted within said frame, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of saidgimba'l, a pair of aligned threaded bores of opposite hand in said rotor coaxial with the axis of rotation thereof, a pair of threaded bolt actuators of opposite hand mating with said bores, means connected to said frame for preventing rotation of said actuators but allowing same to be ejectedfrom the bores, a propulsive charge within said rotor for ejecting the actuators at a high rate of speed from the bores to thereby impart a rotational spin to said rotor upon ignition thereof, and means for igniting the charge.

Y 15. A pyrotechnic gyro comprising a frame, a casing surrounding said frame, a gimbal pivotally mounted within said frame, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of said gimbal, a pair of aligned threaded bores of opposite hand in said rotor coaxial with the axis of rotation thereof, a pair of threaded bolt actuators of opposite hand mating with said bores, means connectedto said frame for preventing rotation of said actuators but allowing same to be ejected from the bores, a propulsive charge within said rotor for ejecting the actuators at a high rate of speed from the bores to thereby impart a rotational spin to said rotor upon ignition thereof, means for caging the rotor prior to firing, and means for igniting the charge.

16. A pyrotechnic gyro comprising a frame, a casing surrounding said frame and secured thereto, an outer gimbal pivot-ally mounted in said frame, an inner gimbal pivotally mounted in said outer gimbal on an axis perpendicular to the pivot axis of the outer gimbal, .a rotor rotatably mounted in said inner gimbal about an axis normal to the axes of said inner and outer gimbals, a pair of aligned threaded bores of opposite hand in said rotor coaxial with the axis of rotation thereof, a pair of threaded bolt actuators of opposite hand mating with said bores, means connected to said frame for preventing rotation of said actuators but allowing same to be ejected from the bores, and a propulsive charge within said rotor for ejecting the actuators at a high rate of speed from the bores to thereby impart a rotationalspin to said rotor upon ignition there-' .bores, means connected to said frame for preventing rotation of said actuators but allowing same to be ejected from the bores, a propulsive charge within said rotor for ejecting the actuators at a high rate of speed from the bores to thereby impart a rotational spin to said rotor upon ignition thereof, means for igniting the charge, and means on said frame for preventing said actuators from engaging said rotor after the charge is fired.

18. A pyrotechnic gyro comprising a casing, .agimbal pivotally mounted within said casing, a rotor rotatably mounted in said gimbal along an axis normal to the pivot axis of said gimbal, a pair of coaxial opposite hand helically splined bores in said rotor coaxial with the axis of rotation thereof, a pair of opposite hand helically splined bolt actuators mating with said bores, a propulsive charge between the adjacent ends of the actuators within said rotor, means for energizing said charge, and means for preventing rotation of said actuators and for guidingly receiving same when they are forced from the rotor.

References Cited by the Examiner UNITED STATES PATENTS 2,960,876 11/1960 Saphra 74--5.'l 2,986,945 6/1961 Riola 74-5.12 3,012,439 12/1961 Ransom et a1 74--5.12 3,017,778 l/l962 Lynn 74-5.12

FRED C. MATTERN, JR., Primary Examiner.

BROUGHTON G. DURHAM, Examiner.

T. W. SHEAR, J. D. PUFFER, Assistant Examiners. 

1. A PYROTECHNIC GYRO COMPRISING A FRAME, A GIMBAL PIVOTALLY MOUNTED WITHIN SAID FRAME, A ROTOR ROTATABLY MOUNTED IN SAID GIMBAL ALONG AN AXIS NORMAL TO THE PIVOT AXIS OF SAID GIMBAL, A PAIR OF ALIGNED HELICALLY SPLINED BORES OF OPPOSITE HAND IN SAID ROTOR COAXIAL WITH THE AXIS OF ROTATION THEREOF, A PAIR OF HELICALLY SPLINED BOLT ACTUATORS OF OPPOSITE HAND MATING WITH SAID BORES, 